The major objective of our proposed study is to elucidate changes in the structure and metabolism of cell surface glycoconjugates which accompany malignant transformation in the colon. We hope to achieve this objective by examining the structures of cell surface glycoconjugates using biochemical, immunochemical and immunological techniques. Following cell surface labeling, we will isolate surface components from colonic tumors, normal tissues and normal and malignant colonic cells. Those which are tumor specific will be extensively characterized. We will compare the synthetic and degradative processes associated with these tumor antigens and compare these processes with those in normal cells and tissues. The turnover and shedding rates of cell surface glycoconjugates will be examined in cultured normal and malignant cells and related to in vivo detection of tumor specific antigens in the body fluids of cancer patients and tumor-bearing animals. Using external cell surface labelling and lectins, we will study the effects differentiating agents have on cell surface components and on the growth properties of cultured cells. We will also compare surface glycoconjugates and cell-cell interactions of cells with different metastatic potential. In this connection, we will examine cell surface glycoconjugates of fibroblasts taken from patients with premalignant conditions such as adenomatosis of the colon and rectum. Finally, we plan to pursue some promising results we have obtained from studies on the effects of dietary fiber constituents on the incidence, degree of malignancy and distribution of colonic tumors in rats.